1. Activate it on network and leave it like that. In this case each user is required to authorize it using its own Google Account.

2. Install it without activating it on network. Not being network activated each user can opt to use it or not.

3. Network activate it and switch on this option: use a single Google Analytics account for the entire network. In this case the entire network will use a single Google Account and users are not able to authorize using their own accounts.